The present invention relates to improved keyboard assembly for electronic musical instruments, and more particularly relates to improvement in construction of a keyboard assembly for electronic musical instruments such as electronic organs in which depression of a key causes engagement between movable and fixed contact in order to selectively switch on a corresponding electric circuit for generation of a corresponding musical tone.
In the construction of the conventional keyboard assembly of the above-described type, a movable contact given in the form of a leaf spring is provided for each key and a fixed contact common to all keys is arranged below the movable contacts. When any key in the keyboard is depressed during performance on the musical instrument, its associated bottom actuator thrusts down a corresponding movable contact into provisional contact with a corresponding portion of the fixed contact and a corresponding electric circuit is switched on for generation of a musical tone.
In this case, it is necessary to register a number of movable contacts at correct positions on a key frame with high mechanical preciseness. This assembly work is considerably complicated and, therefore, very time and labor consuming. Use of a in number of movable contacts inevitably results in great increase in the number of mechanical and electrical parts. Further, use of the leaf spring type movable contact tends to generate undesirable chattering during engagement between the movable and fixed contacts which fatally degrades acoustic effect of the musical tones to be generated. In addition, use of a plurality of movable contacts in the circuits makes it impossible to use the printed circuit technique in construction of the keyboard assembly which is effective for building a compact construction.